WO2018117598A1

WO2018117598A1 - Non-oriented electrical steel sheet and manufacturing method therefor

Info

Publication number: WO2018117598A1
Application number: PCT/KR2017/015023
Authority: WO
Inventors: 김재훈; 이현주; 김용수; 신수용
Original assignee: 주식회사 포스코
Priority date: 2016-12-19
Filing date: 2017-12-19
Publication date: 2018-06-28
Also published as: JP6821055B2; US11060170B2; US20200080175A1; CN110088319B; EP3556878A4; KR20180070949A; KR101902438B1; EP3556878A1; JP2020504787A; CN110088319A

Abstract

According to one embodiment of the present invention, a non-oriented electrical steel sheet comprises, by wt%, 2.0-3.5% of Si, 0.3-2.5% of A1, 0.3-2.5% of Mn, 0.0005-0.03% of Ga and/or Ge individually or as the sum thereof, and the balance of Fe and inevitable impurities, and satisfies the following formula 1. [Formula 1] 0.2 < ([Si] + [Al]+0.5 × [Mn])/(([Ga] + [Ge]) × 1000) < 5.27 (In which [Si], [Al], [Mn], [Ga] and [Ge] respectively indicate the amounts (wt%) of Si, Al, Mn, Ga and Ge.)

Description

【Specification】

[Name of invention]

Non-oriented electrical steel sheet and manufacturing method

Technical Field

It relates to a non-oriented electrical steel sheet and a method of manufacturing the same.

[Technique to become background of invention]

Recently, the demand for non-oriented electrical steel sheets used for automobile driving motors is rapidly increasing as awareness of eco-friendly vehicles is increased to reduce fine dust and reduce greenhouse gases. Unlike conventional internal combustion engine cars that use engines, eco-friendly vehicles (hybrids, full lugs-in-hybrids, electric cars, fuel cell vehicles) are driven by motors, and various motors other than allergic drive motors are needed.

Is closely associated with a variety of motor efficiency, including the traveling distance of the green vehicle drive motor, and efficiency of these motors is associated directly with the magnetization of the electrical steel ^sheet: is. Therefore, in order to increase the mileage, it is essential to use non-oriented electrical steel sheet having excellent magnetic properties.

Unlike general motors, driving motors should show excellent characteristics in all areas from low speed to high speed, unlike general motors. Therefore, large torque should be produced at low speed or acceleration, and the loss should be small at constant speed and high speed driving. Suitable properties are required.

In order to achieve these characteristics, in the non-oriented electrical steel sheet, which is a motor core material, it has to have a large magnetic flux density characteristic at low speed rotation, low frequency high frequency loss at high speed rotation, and withstand centrifugal force generated at high speed rotation. High mechanical strength is required.

As non-oriented electrical steel sheet for environmentally friendly automobiles, non-oriented electrical steel sheet including segregation elements such as Sn, Sb and P has been proposed. However, this has a problem that the cold rolling is difficult because of brittleness. Therefore, the technology of lowering the content of Sn, Sb, and P used as segregation elements to reduce the content of Si and increase the amount of ΑΙ,-Μη to improve the cold rolling property or to further improve the cold rolling property is proposed. It became. But, like cold rolling Focusing on productivity deteriorates magnetism and degrades motor characteristics.

[Contents of the Invention]

[Problems to be solved] ^■

One embodiment of the present invention to provide a non-oriented electrical steel sheet containing a new additive element that can replace Sn, Sb, P.

Another embodiment of the present invention is to provide a method for producing a non-oriented electrical steel sheet.

[Measures of problem]

Non-oriented electrical steel sheet according to an embodiment of the present invention by weight% of Si: 2.0 to 3.5%, A1: 0.3 to 2.5%, Mn: 0.3 to 2.5% and one or more of Ga and Ge, respectively, or a total thereof As such, 0.0005 to 0.03% and the balance include Fe and inevitable impurities, and satisfy the following Equation 1.

[Equation 1]

0.2 <([Si] + [Al] + 0.5x [Mn]) / (([Ga] + [Ge]) 1000) <5.27

([Si], [Al], [Mn], [Ga] and [Ge] are Si, Al, Mn, Ga and

Content of Ge (% by weight).)

example. Of the invention. Non-oriented electrical steel sheet according to one embodiment N: 0.0040% or less (excluding OT), C: 0.0040% or less (excluding 0%), S: 0.0040% or less (excluding 0%), Ti : 0.0030% or less (excluding 0%), Nb: 0.0030% or less (excluding 0%) and V: 0.0040% or less (excluding 0%).

The non-oriented electrical steel sheet according to one embodiment of the present invention may include Ga: 0.0005 to 0.02 weight% and Ge: 0.0005 to 0.02 weight%.

Non-oriented electrical steel sheet according to an embodiment of the present invention may satisfy the following equation 2.

[Equation 2]

3.3 <([Si] + [Al] + 0.5 x [Mn]) <5.5

(However, [Si], [Al] and [Mn] represent the content (% by weight) of Si, / and Mn, respectively.)

Electrical non-oriented according to an embodiment of the present invention is the strength of the steel sheet eu ^"texture when tested in a l / l to about 2t / 4t zone of the steel pipe thickness ratio XRD I P200 (P211 + P310)> 0.5 may be satisfied. In this case, l / 2t means 1/2 thickness of the overall steel sheet thickness, l / 4t means 1/4 thickness of the overall steel sheet thickness, and P200 means that in the XD test, the <200> plane is 15 in the vertical direction of the steel sheet. It means the surface strength of the aggregate structure lying in parallel within the degree, P211 means the surface strength of the texture structure in which the <211> plane lies in parallel within 15 degrees in the vertical direction of the steel sheet, P310 is the <310> plane It means the surface strength of the aggregate which lies in parallel within 15 degrees of this steel plate vertical direction.

Non-oriented electrical steel sheet according to an embodiment of the present invention may have an average grain size of 50 to 95 ni.

The non-oriented electrical steel sheet according to the embodiment of the present invention may have a magnetic permeability of 8000 or more at 100 A / m and a coercive force at B = 2.0T of 40 A / m or less.

Non-oriented electrical steel sheet according to an embodiment of the present invention may have a specific resistance of 55 to 75μΩ · αη.

Method for producing a non-oriented electrical steel sheet according to an embodiment of the present invention by weight% Si: 2.0 to 3.5%, A1: 0.3 to 2.5%, Mn: 0.3 to 2.5% and one or more of Ga and Ge, respectively Or 0.0005 to 0.03% of the total amount and the balance include Fe and an unavoidable impurity, and heating a slab satisfying Equation 1 below; Hot rolling the slab to produce a hot rolled sheet; Cold rolling the hot rolled sheet to produce a cold rolled sheet and final annealing the cold rolled sheet.

[Equation 1]

0.2 <(iSi) + [Al] + 0.5 x [Mn]) / (([Ga] + [Ge]) xi000) <5.27

([Si], [Al], [Mn], [Ga] and [Ge] are Si, Al, Mn, Ga and

Content of Ge (shows the weight «)

Slabs: N: 0.0040% or less (excluding 0%), C: 0.0040% or less (excluding 0%), S: 0.0040% or less (excluding 0%), Ti: 0.0030% or less (0% Excluded),

Nb: 0.0030% or less (excluding 0%) and V: 0.0040% or less (excluding ◦%) may be further included.

The slab may comprise Ga: 0.0005 to 0.02 weight% and Ge: 0.0005 to 0.02 weight%. The slab may satisfy the following formula 2.

[Equation 2]

3.3 <([S i] + [Al] +0.5 x [Mn]) <5.5

(However, [Si], [A1] and [Mn] represent the content (% by weight) of Si, A1 and Mn, respectively.)

Prior to heating the slab, manufacturing molten steel; Adding Si alloy iron, A 1 iron alloy, and Mn alloy iron to molten steel; And adding at least one of Ga and Ge to the molten steel and continuously casting the slab.

After preparing the hot rolled sheet, the method may further include hot-rolled sheet annealing.

【Effects of the Invention】

Non-oriented electrical steel sheet and manufacturing method according to an embodiment of the present invention is excellent in magnetic as well as productivity.

[Specific contents to carry out invention]

Terms such as first, second and third are used to describe various parts, components, regions, layers and / or sections, but are not limited to these. These terms are only used to distinguish which part, component, region, layer or section, and the other part, component, region, layer or ^section. Accordingly, the first portion, component, region, layer or section described below may be referred to as the second portion, component, region, layer or section without departing from the scope of the invention.

The terminology used herein is for reference only to specific embodiments and is not intended to limit the invention. As used herein, the singular forms “a,” “an,” and “the” include plural forms as well, unless the phrases clearly indicate the opposite. As used herein, the meaning of "comprising" embodies a particular characteristic, region, integer, step, operation, element and / or component, and the presence of another characteristic, region, integer, step, operation, element and / or component or It does not exclude the addition.

When a part is referred to as "on" or "on" another part, it may be on or above another part or between May be involved. In contrast, if a part is mentioned as "just above" ¹ of another part, no other part is intervened in between.

Although not defined otherwise, all terms including technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. Commonly defined terms used are additionally interpreted to have a meaning consistent with the related technical literature and the presently disclosed contents, and are not interpreted in an ideal or very formal sense unless defined.

Also, unless stated otherwise% means weight% and lppm is

0.0001% by weight.

In an embodiment of the present invention, the meaning of further including an additional element means to include a residual amount of iron (Fe) by an additional amount of the additional element. Hereinafter, embodiments of the present invention will be described in detail so that those skilled in the art can easily practice. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. .

In one embodiment of the present invention, not only the composition of the non-oriented electrical steel sheet, in particular, the range of the main additives S i, Al, and Mn, but also the amount of trace elements Ga and Ge are limited, thereby remarkably increasing the texture and magnetic properties. To improve.

The non-oriented electrical steel sheet according to an embodiment of the present invention is increased in% by Si: 2.0 to 3.5%, Al: 0.3 to 2.5%, Mn: 0.3 to 2.5% and at least one of Ga and Ge. 0.0005 to 0.03%, and the balance alone or in total, include Fe and unavoidable impurities, respectively.

First, the reason for component limitation of a non-oriented electrical steel sheet is demonstrated.

Si: 2.0 to 3.5% by weight

Silicon (S i) serves to lower the iron loss by increasing the specific resistance of the material, if too little added, may not be effective in improving the high frequency iron loss. On the contrary too. If a large amount is added, the hardness of the material may increase, resulting in an extreme deterioration of the cold rolling property, resulting in inferior productivity and punchability. Therefore, S i can be added in the above-mentioned range. Al: 0.3-2. 5 wt%

Aluminum (Al) serves to lower the iron loss by increasing the specific resistance of the material, if too little is added to reduce the high-frequency iron loss, and the nitride is finely formed may degrade the magnetism. Conversely, too much addition can cause problems in all processes such as steelmaking and continuous casting, which can greatly reduce productivity. Therefore, A1 can be added in the above-mentioned range.

Mn: 0.3-2. 5 wt%

Manganese (Mn) increases the specific resistance of the material to improve iron loss and form sulfides. If too little is added, MnS may be finely precipitated and degrade the magnetism. On the contrary, if too much is added

[111] The magnetic flux density can be reduced by promoting the formation of aggregates. Therefore, Mn can be added in the above-mentioned range.

Ga and Ge: 0.000 to 0.03 increment%

Gallium (Ga) and germanium (Ge) segregate on the surface and grain boundaries of the steel sheet to inhibit surface oxidation during annealing and improve the texture of the aggregates. In one embodiment of the present invention, one or more of Ga and Ge may be included. That is, only Ga may be included alone, only Ge may be included alone, or Ga and Ge may be included simultaneously. When only Ge is included alone, Ge may be included in 0.0005 to 0.03% by weight. When only Ga is included alone, Ga may be included in an amount of 0.0005 to 0.03% by weight. When including Ga and Ge at the same time, the total amount of Ga and Ge may be included so as to be 0.0005 to 0.03% by weight. If one or more of Ga and Ge is added too little, there is no effect, and if it is added too much, it will be segregated at the grain boundary, which will lower the toughness of the material and lower the productivity compared to the magnetic improvement. Specifically, Ga and Ge may be simultaneously included, and 0.0005 to 0.02 wt% of Ga and 0.0005 to 0.02 wt% of Ge may be included. More specifically, it may include 0.0005 to 0.01% by weight of Ga and 0.0005 to 0.01% by weight of Ge.

N: 0.0040 wt% or less

Nitrogen (N) not only forms fine and long A 1 N precipitates inside the base material, but also combines with other impurities to form fine nitrides to inhibit grain growth. The iron loss is worsened, so it is preferable to limit the amount to 0.0040% by weight or less, and more specifically, 0.0030% by weight or less.

C: 0.0040 wt% or less

Since carbon (C) causes magnetic aging and combines with other impurity elements to form carbides, thereby lowering the magnetic properties, it is preferable to limit the carbon content to 0.040% by weight or less, and more specifically, 0.0030% by weight or less.

S: 0.0040 wt% or less

Sulfur (S) reacts with Mn to form sulfides, such as MnS, thereby reducing grain growth and inhibiting magnetic migration, and therefore, the sulfur (S) is preferably controlled at 0.0040% by weight or less. More preferably, it should be limited to α.0030% by weight or less.

Ti: 0.0030 wt% or less

Titanium (Ti) forms carbides or nitrides to inhibit grain growth and magnetic migration, so it is 0.0030% by weight or less, more specifically 0.0020% by weight? It is good to restrict to the following.

Nb: 0.0030 wt% or less

Since niobium (Nb) forms carbides or nitrides and serves to inhibit grain growth and magnetic migration, the niobium (Nb) is preferably limited to 0.0030% by weight or less, more specifically 0.0020% by weight or less.

V: 0.0030 wt% or less

Since the bar (V) forms carbides or nitrides and serves to inhibit grain growth and migration, it is preferable to limit the content to 0.0030% by weight or less, more specifically, 0.0020% by weight or less.

Other impurities

In addition to the elements described above, it may contain inevitable impurities such as Mo, Mg and Cu. Although these elements are trace amounts, they may cause magnetic deterioration through the formation of inclusions in the steel, etc., and therefore they should be controlled at 0.005 wt% or less and Cu: 0.025 wt% or less.

Non-oriented electrical steel sheet according to an embodiment of the present invention satisfies the following equation 1. [Equation 1]

0.2 <([Si] + [Al] + 0.5x [Mn]) / (([Ga] + [Ge]) xi000) <5.27

(However, [Si], [Al], [Mn], [Ga], and [Ge] represent the contents (increase%) of Si, Al, Mn, Ga, and Ge, respectively.)

When the value of Equation 1 is less than 0.2, the effect of adding Ga and Ge is insignificant, and the magnetism may be deteriorated. When the value of Equation 1 exceeds 5.27, the large amount of Ga and Ge is inferior to the texture, the saturation magnetic flux density is reduced, the high frequency magnetic improvement effect can be lost.

[Equation 2]

3.3 <([Si] + [Al] + 0.5 x [Mn]) <5.5

(However, [Si], [Al] and [Mn] represent the content (% by weight) of Si, Al and Mn, respectively.)

When satisfy | filling the value of Formula 2 mentioned above, cold rolling property can be ensured.

Of the present invention. In one practical example, the texture is improved by adding a specific amount of Ga and Ge. More specifically, when the XRD test of the l / 2t to l / 4t region of the steel sheet thickness, the strength ratio of the texture may satisfy P200 I (P211 + P310)> 0.5. In this case, l / 2t is the whole _. 1 / 2t means the thickness of the steel sheet, l / 4t means 1/4 thickness of the total steel sheet thickness, P200 in the XRD test, the <200> plane is placed parallel to within 15 degrees in the vertical direction of the steel sheet It means the surface strength of the texture, P211 means the surface strength of the texture in which the <211> plane lies parallel to within 15 degrees in the vertical direction of the steel sheet, P310 is 15 degrees in the vertical direction of the steel sheet <310> It refers to the surface strength of the aggregates that lie parallel within. The aggregated structure (ie, 1) // <200>) in which the <200> plane lies parallel to the steel plate in the vertical direction within 15 degrees includes the biaxial axis for magnetization, and the larger the ratio, the better the magnetism. In addition, the aggregated structure in which the <211> plane lies parallel to the steel plate vertical direction within 15 degrees (ie, ND / <211>) and the aggregated structure where the <310> plane lies parallel to the steel plate vertical direction within 15 degrees. (Ie, ND // <310>) is close to the hard magnetization axis, and the smaller the ratio, the better the magnetism. Of the present invention In one embodiment, the improvement of the magnetic structure in the low magnetic field region through the improved aggregate organization, which is analyzed to play a key role in improving the high frequency iron loss.

Non-oriented electrical steel sheet according to an embodiment of the present invention may have an average grain size of 50 to 95. The high frequency iron loss is excellent in the above-mentioned range.

Non-oriented electrical steel sheet according to an embodiment of the present invention is improved in permeability and coercivity is suitable for high speed rotation. As a result, it can contribute to the improvement of mileage when applied to motors of eco-friendly cars. Specifically, the non-oriented electrical steel sheet according to one embodiment of the present invention may have a magnetic permeability of 8000 or more and a coercive force of 40 A / m or less at B = 2.0T.

Non-oriented electrical steel sheet according to an embodiment of the present invention may have a specific resistance of 55 to 75μΩ · α. If the resistivity is too high, the magnetic flux density will be inferior, making the motor unsuitable.

Method for producing a non-oriented electrical steel sheet according to an embodiment of the present invention by weight% Si: 2.0 to 3.5%, A1: 0.3 to 2.5%, Mn: 0.3 to 2.5% and one or more of Ga and Ge, respectively Or 0.0005 to 0.03% of the total amount and the balance include Fe and unavoidable impurities, and heating the slab satisfying the following formula 1; Hot rolling a slab to produce a hot rolled sheet; Cold rolling of the hot rolled sheet to prepare a cold rolled sheet and the final annealing of the molten sheet.

First heat the slab. The reason for limiting the addition ratio of each composition in the slab is the same as the reason for limiting the composition of the non-oriented electrical steel sheet described above, and thus repeated description is omitted. Since the composition of the slab is not substantially changed in the manufacturing process of hot rolling, hot rolling annealing, cold rolling, final annealing, and the like, the composition of the slab and the composition of the non-oriented electrical steel sheet are substantially the same.

The slab is produced by the molten steel; Adding Si alloy iron, A1 alloy iron, and Mn alloy iron to molten steel; And at least one Ga and Ge increase in molten steel, and can be produced by continuous casting. Si alloy iron, A1 alloy iron, Mn alloy iron, Ga, Ge and the like can be added to adjust to correspond to the composition range of the above-described slab. Charge the slabs into a furnace and heat them to 1100 to 1250 ^° C. When heated at a temperature above 1250 ^° C, the precipitate may be re-dissolved to be finely precipitated after hot rolling.

The heated slabs are hot rolled to 2 to 3.2 kPa to produce hot rolled plates. Finishing temperature in the step of manufacturing a hot rolled sheet may be 800 to 1000 ^° C.

After preparing the hot rolled sheet, the method may further include hot-rolled sheet annealing. At this time, the hot rolled sheet annealing temperature may be 850 to 1150 ^° C. If the hot-rolled sheet annealing temperature is less than 850 ^° C, the structure does not grow or finely grow, so there is little synergistic effect of the magnetic flux density. If the annealing temperature exceeds 1150 ^° C, the magnetic properties deteriorate, and the rolling due to the deformation of the plate shape Workability can worsen. More specifically, the temperature range may be 950 to 1125 ° C. More specifically, the annealing temperature of the hot rolled sheet is 900 to 1100 ^° C. Hot-rolled sheet annealing is performed to increase the orientation favorable to the magnetic, if necessary, may be omitted.

Next, the hot rolled sheet is pickled and cold rolled to a predetermined sheet thickness. Although it may be applied differently according to the thickness of the hot rolled sheet, it may be cold rolled so that the final thickness may be 0.2 to 0.65 kPa by applying a reduction ratio of 70 to 95%.

The final cold rolled cold rolled sheet is subjected to maximum annealing so that the average grain size is 50 to 95. The final annealing temperature can be from 750 to 1050 ^° C. ^{'If the} final annealing silver is too low, recrystallization does not occur too much. If the final annealing temperature is too high, rapid growth of crystal grains may occur, causing magnetic flux density and high frequency iron loss to become thermal. More specifically, the temperature of 900 to loocrc Final annealing at In the final annealing process, all the processed tissue formed in the pre-rolling step can be recrystallized (ie, 99% or more).

Hereinafter, the present invention will be described in more detail with reference to Examples. However, these examples are only for illustrating the present invention, and the present invention is not limited thereto.

Example 1

To prepare a slab composition as shown in Table 1. C, S, N, Ti, Nb, V and the like except for the components shown in Table 1 were all controlled at 0.003% or less. The slab was heated to 1150 ^° C., and hot-rolled at 850 ^° C. to produce a hot rolled sheet having a plate thickness of 2.0 kPa. The hot rolled hot rolled sheet was annealed at 1100 ° C. for 4 minutes and then pickled. After the cold rolling, the plate thickness was 0.25 kPa, and the final annealing was performed at 1000 ^° C. for 38 seconds. Magnetism was determined by the average value of the rolling direction and the vertical direction using a single sheet tester is shown in Table 2 below. Permeability is the magnetic permeability at 100A / m, and coercive force is the coercive force at B = 2.0T. The aggregates were cut into steel plates up to 1/2 t and each surface strength was determined using the XRDO (Line Diffraction Analysis) test method.

Table 11

Table 2

As shown in Table 1 and Table 2, in the case of the example steel grades, the aggregate structure is improved, so that the permeability is large and the coercive force is small. On the other hand, in the case of comparative steel grades in which the addition amount of Ga and Ge is out of the scope of the present invention, the aggregate structure was not improved, so the permeability and coercivity were inferior, and grain growth was also inferior.

The present invention is not limited to the embodiments and can be manufactured in various different forms, and those skilled in the art to which the present invention pertains may change to other specific forms without changing the technical spirit or essential features of the present invention. It will be appreciated that it may be practiced. Therefore, it should be understood that the embodiments described above are exemplary in all respects and not restrictive.

Claims

[Claim 1] Claim 1 in weight% of Si: 2.0 to 3.5%, A1: 0.3 to 2.5%, Mn: 0.3 to 2.5%, and one or more of _Ga and Ge, each alone or in a sum, 0005 to 0.03 ¾> and the balance include Fe and unavoidable impurities, the non-oriented electrical steel sheet that satisfies the following formula (1).

[Equation 1]

0.2 <([Si] + [Al] +0.5 [Mn]) / (([Ga] + [Ge]) 1000) <5.27

(However, [Si], [Al], [Mn], [Ga], and [Ge] represent the contents (% by weight) of Si, Al, Mn, Ga, and Ge, respectively.)

[Claim 2]

The method of claim 1,

N: 0.0040% or less (excluding 0%), C: 0.0040% or less (excluding 0%), S: 0.0040% or less (excluding 0%), Ti: 0.0030% or less (excluding 0%) ), Nb: 0.0030% or less (excluding%) and V: 0.0040% or less (excluding 0%).

[Claim 3]

The method of claim 1,

Non-oriented electrical steel sheet comprising Ga: 0.0005 to 0.02% by weight and Ge: 0.0005 to 0.02% by weight.

[Claim 4]

The method of claim 1,

Non-oriented electrical steel sheet satisfying the following formula 2.

[2]

3.3 <([Si] + [Al] + 0.5X [Mn]) <5.5

(However, [Si], [Al] and [Mn] represent the contents (increase%) of Si, AΓ and Mn, respectively.)

[Claim 5]

The method of claim 1,

When XRD test of l / 2t to l / 4t area of steel plate thickness, Non-oriented electrical steel sheet whose strength ratio satisfies P200 I (P211 + P310)> 0.5.

(However, l / 2t means 1/2 thickness of the total steel sheet thickness, l / 4t means 1/4 thickness of the entire steel sheet thickness, and P200 is the X200 test, the <200> plane is in the vertical direction of the steel sheet. It means the surface strength of the aggregate structure lying parallel within 15 degrees, P211 means the surface strength of the texture structure is placed parallel to within 15 degrees in the vertical direction of the steel sheet, P310 is <310> It means the surface strength of the aggregate where the surface lies ^' parallel within 15 degrees ^{' in the} vertical direction of the steel sheet.)

[Claim 6]

The method of claim 1,

Non-oriented electrical steel sheet having an average grain size of 50 to ^■ 9 zm.

[Claim 7]

The method of claim 1,

Non-oriented electrical steel sheet with a permeability of 100 A / m or more and 8000 and a coercive force of 40 A / m or less at B = 2.0T.

[Claim 8]

The method of claim 1,

Non-oriented electrical steel sheet having a specific resistance of 55 to 75 μΩ · αη.

[Claim 9]

% By weight of Si: 2.0 to 3.5%, A1: 0.3 to 2.5%, Mn: 0.3 to 2.5% and one or more of Ga and Ge, alone or in combination, ^' 0.0005 to 0.03% and the balance are Fe and unavoidable impurities Comprising, heating a slab that satisfies Formula I;

Hot rolling the slab to produce a hot rolled sheet;

Cold rolling the hot rolled sheet to produce a cold rolled sheet; and

Method for producing a non-oriented electrical steel sheet comprising the final annealing the cold rolled sheet.

[Equation 1]

0.2 <([Si] + [Al] + 0.5x [Mn]) / (([Ga] + [Ge]) X1000) <5.27

([Si], [Al], [Mn], [Ga] and [Ge] are Si, Al, Mn, Ga and Content of Ge (increase%).)

[Claim 10]

According to claim 19,

The slab is N: 0.0040% or less (except 0%), C: 0.0040% or less (except 0%), S: 0.0040% or less (except 0%), Ti: 0.0030% or less (0% And Nb: 0.0030% or less (except 0%) and V: 0.0040% or less (except 0%).

[Claim 11]

The method of claim 9,

The slab is Ga: 0.0005 to 0.02% by weight and Ge: 0.0005 to 0.02% by weight manufacturing method of a non-oriented electrical steel sheet.

[Claim 12]

In paragraph 9 _. In

The slab is a method of manufacturing a non-oriented electrical steel sheet satisfying the following formula 2. [Equation 2]

3.3 <([Si] + [Al] + 0 5x [Mn]) <5.5

(However, [Si], [A1] and [Mn] represent the contents (% by weight) of Si, A1 and Mn, respectively.)

[Claim 13]

The method of claim 9,

Prior to heating the slab,

Manufacturing molten steel;

Adding Si alloy iron, A1 alloy iron and Mn alloy iron to the molten steel; And

Adding at least one of Ga and Ge to the molten steel, and continuously casting the slab to produce a slab; Method for producing a non-oriented electrical steel sheet further comprising. [Claim 14]

The method of claim 9,

After manufacturing the hot rolled sheet,

Non-oriented further comprising the step of annealing the hot rolled sheet Method for manufacturing electrical steel sheet.